Comparative analysis between measured and calculated concentrations of major actinides using destructive assay data from Ohi-2 PWR

In the paper, we assess the accuracy of the Monte Carlo continuous energy burnup code (MCB) in predicting final concentrations of major actinides in the spent nuclear fuel from commercial PWR. The Ohi-2 PWR irradiation experiment was chosen for the numerical reconstruction due to the availability of the final concentrations for eleven major actinides including five uranium isotopes (U-232, U-234, U-235, U-236, U-238) and six plutonium isotopes (Pu-236, Pu-238, Pu-239, Pu-240, Pu-241, Pu-242). The main results were presented as a calculated-to-experimental ratio (C/E) for measured and calculated final actinide concentrations. The good agreement in the range of ±5% was obtained for 78% C/E factors (43 out of 55). The MCB modeling shows significant improvement compared with the results of previous studies conducted on the Ohi-2 experiment, which proves the reliability and accuracy of the developed methodology.

Study on the Experimental Ratio of New Cement-Based Composite Insulation Board

In the experiment, polystyrene particles, cement, fly ash, activator and fibers were used as raw material to prepare new cement-based composite insulation board by compression molding. Through the determination of best content of fly ash, the effects of fly ash on strength of composite insulation board were studied. Through the determination of the optimal content of activators, the effects of activators on the mechanical properties of composite insulation board were studied. Through the determination of the optimal dosage of fibers, the effects of fibers on performance of composite insulation board were studied. The morphology in the samples was observed by scanning electron microscopic, and the action mechanism of each component was studied.

OPEN AND HIDDEN CHARM IN PROTON–NUCLEUS AND HEAVY-ION COLLISIONS

We review dynamical and thermal models for the collectivity and the suppression pattern of charmed mesons — produced in proton–nucleus and nucleus–nucleus collisions at SPS (~158 A GeV) and RHIC energies (~21 A TeV). In particular, we examine the charmonium "melting" and the "comover dissociation" scenarios — implemented in a microscopic transport approach — in comparison to the available data from the SPS and RHIC. The analysis shows that the dynamics of c and [Formula: see text] quarks. quarks at RHIC are dominated by partonic or "pre-hadronic" interactions in the strongly coupled plasma stage and can neither be modeled by "hadronic" interactions nor described appropriately by color screening alone. Both the "charmonium melting" and the hadronic "comover absorption and recreation model" are found, however, to be compatible with the experimental observation at SPS energies; the experimental ratio of Ψ′/J/Ψ versus centrality clearly favors the "hadronic comover" scenario. We find that the collective flow of charm in the purely hadronic Hadron-String Dynamics (HSD) transport appears compatible with the data at SPS energies, but the data at top RHIC energies are substantially underestimated. Thus, the large elliptic flow v2 of D-mesons and the low RAA(pT) of J/Ψ seen experimentally have to be attributed to early interactions of non-hadronic degrees of freedom. Simultaneously, we observe that non-hadronic interactions are mandatory in order to describe the narrowing of the J/Ψ rapidity distribution from pp to central Au + Au collisions at the top RHIC energy of [Formula: see text]. Additionally we demonstrate that the strong quenching of high-pTJ/Ψ's in central Au + Au collisions indicates that a large fraction of final J/Ψ mesons is created by a coalescence mechanism close to the phase boundary. Throughout this review we, furthermore, provide predictions for charm observables from Au + Au collisions at FAIR energies of 25–35 A GeV.

Landau–Zener Effect in Superfluid Nuclear Systems

The Landau–Zener effect is generalized for many-body systems with pairing residual interactions. The microscopic equations of motion are obtained and the 14C decay of 223Ra spectroscopic factors are deduced. An asymmetric nuclear shape parametrization given by two intersected spheres is used. The single particle level scheme is determined in the frame of the superasymmetric two-center shell model. The deformation energy is computed in the microscopic–macroscopic approximation. The penetrabilities are obtained within the WKB approximation. The fine structure of the cluster decay analyzed in the frame of this formalism gives a very good agreement with the experimental ratio of partial half-lives for transition to the first excited state and to the ground state.

Luminescence Properties of Si-Doped GaN and Evidence of Compensating Defects As the Origin of the Yellow Luminescence

We investigate the optical properties of n-type Gallium Nitride (GaN) with concentrations ranging from 5×1016 to 7×1018 cm−3. The near-band edge ultraviolet (UV) transition increases monotonically with the doping concentration. The photoluminescence linewidth of the near-bandgap optical transition increases from 47 to 78 meV as the doping concentration is increased. The broadening is modeled by taking into account potential fluctuations caused by the random distribution of donor impurities. Excellent agreement is found between experimental and theoretical results. We also investigate the origin of the yellow luminescence in GaN. At low excitation densities the experimental ratio of the UV-to-yellow photoluminescence does not change significantly as the doping concentration is increased by two orders of magnitude. Analysis of the luminescence in terms of a theoretical model indicates that the yellow luminescence is due to compensating impurities or defects.

Multi-Airfoil Navier–Stokes Simulations of Turbine Rotor–Stator Interaction

An accurate numerical analysis of the flows associated with rotor–stator configurations in turbomachinery can be extremely helpful in optimizing the performance of turbomachinery. In this study the unsteady, thin-layer, Navier–Stokes equations in two spatial dimensions are solved on a system of patched and overlaid grids for an axial-turbine rotor–stator configuration. The governing equations are solved using a finite-difference, upwind algorithm that is set in an iterative, implicit framework. Results are presented in the form of pressure contours, time-averaged pressures, unsteady pressures, amplitudes, and phase. The numerical results are compared with experimental data and the agreement is found to be good. The results are also compared with those of an earlier study, which used only one rotor and one stator airfoil. The current study uses multiple rotor and stator airfoils and a pitch ratio that is much closer to the experimental ratio. Consequently, the results of this study are found to be closer to the experimental data.

Optical properties of monolayer NbS2 suspensions

We present a theory for the anisotropic optical and magnetic properties of monolayer NbS2 platelets suspended in water and oriented in a magnetic field. We compare experimental data obtained by Liu and Frindt and calculated properties using a dielectric function obtained from a Drude–Lorentz fit to reflectivity data for the bulk material. The anisotropic magnetic susceptibility of the material allows a separate study of the extinction coefficients of light with polarizations perpendicular and parallel to the flake plane. We estimate the contributions from scattering and absorption using the fitted dielectric constant; and we find that for monolayer flakes, absorption should be the dominant mechanism. We also estimate the effects of local-field corrections on absorption and scattering to be small. A puzzling feature is that the experimental ratio of the optical anisotropy for the extinction coefficients fails to satisfy a predicted 2:1 ratio suggested by symmetry considerations.

The Therapeutic Equivalence of IM and PO Administration of Morphine – 1:3 or 1:6?

When alternating between the intramuscular and oral routes of morphine adminstration, dosage adjust-ments must be made according to differences in rel-ative analgesic potency. While study has shown that six times as much morphine is required orally as intramuscularly to obtain the same total analgesic effect, anecdotal experience suggests that three times as much drug is required orally as is required parenterally. The following examines the arguments both for and against the two approaches to dose adjustment when alterations in route of administration are indicated. There is no compelling reason to change the use of the 1:3 ratio in cancer-related pain. The original experimental ratio of 1:6 is only an apparent inconsistency in that the conditions of dosing and other factors are most likely responsible for this apparent discrepancy. It will only be with a well-controlled study, however, conducted under appropriate conditions, that the 1:3 ratio can be confirmed.